Plain English Meaning
A flashing light at the airport that helps pilots spot the airport from the air. The colors of the flashes tell you what kind of airport it is. If it is on during the day, it usually means the weather is poor.
Full Definition
A rotating light installed at an airport that flashes a specific sequence of colors to identify the airport from the air at night or in reduced visibility. White-and-green flashes identify a lighted civilian land airport; white-and-yellow identify a lighted water airport; white-white-green identify a lighted military airport. When operated during daytime hours, it generally indicates that the ceiling is below 1,000 feet or visibility is less than 3 statute miles in Class B, C, D, or E surface areas.
Context Anchor
Seen on airport diagrams and , and in when looking for the airport at night or when the airport is to see.